Here's why it's complex and what's involved:
* Manifold: You'll need a dual-Weber intake manifold specifically designed for the 258 AMC engine. These are not readily available and often require sourcing from specialty suppliers or potentially custom fabrication.
* Carburetion Tuning: Weber carburetors are known for their performance potential, but they require precise tuning. Getting the fuel mixture and air/fuel ratio correct for optimal performance and drivability will involve significant adjustment and likely professional tuning. Incorrect tuning can lead to poor performance, poor fuel economy, or even engine damage.
* Air Cleaner: You'll need a suitable air cleaner designed to accommodate two Weber carburetors. Again, this might require custom fabrication or modification.
* Fuel Delivery: The stock fuel pump and fuel lines may need upgrading to support the increased fuel flow demands of two carburetors. A higher-volume fuel pump might be necessary.
* Wiring: While less critical than other aspects, some modifications to your existing wiring might be necessary depending on the specific Weber setup you choose. Some Weber carburetors include electric choke components.
* Emission Compliance: Depending on your location and the vehicle's year, this conversion may affect your vehicle's emission compliance. You might need to have it inspected and potentially make further modifications to meet local regulations.
In short, while technically possible, replacing a Carter one-barrel with two Webers on a CJ7 258 is a substantial project that's best tackled by someone with experience in engine modifications and carburetion. It's not a beginner-level modification. Consider the cost of parts, labor (if you're not doing it yourself), and potential tuning costs before undertaking this conversion. It's often more expensive and complicated than it initially appears.
